3128. 直角三角形

直角三角形

• 难度: medium
• 原始链接: https://leetcode.cn/problems/right-triangles
• 标签: 枚举

解法一: 枚举

go

func numberOfRightTriangles(grid [][]int) int64 {
  rLen := len(grid)
  cLen := len(grid[0])
  rows := make([]int, rLen)
  cols := make([]int, cLen)
  for r := 0; r < rLen; r++ {
    for c := 0; c < cLen; c++ {
      rows[r] += grid[r][c]
      cols[c] += grid[r][c]
    }
  }
  ans := int64(0)
  for r := 0; r < rLen; r++ {
    for c := 0; c < cLen; c++ {
      if grid[r][c] == 1 {
        ans += int64((rows[r] - 1) * (cols[c] - 1))
      }
    }
  }
  return ans
}